1. Field of the Invention
The present invention relates generally to collapsible shelters and more particularly to light weight, low cost shelters which can be made in a variety of sizes to accommodate persons, equipment or vehicles.
2. Discussion of the Prior Art
Various types of collapsible structures have been suggested in the past. Most of these structures are in the nature of small foldable tents, or the like, for use in providing personnel shelter. Typically, the prior art structures embody a ground engaging base of some type to which upwardly extending cover support members are inter-connected. Exemplary of such structures are those described in U.S. Pat. Nos. 3,995,649 and 3,540,458 issued to Robichand and Osterhoudt respectively.
In the Robichand patent the base structure, or frame 11, rests upon the ground and in one form of the invention comprises cooperatively associated telescoping members. In another form of the Robichand invention the base comprises a hinged rectangular structure which rests on the ground. In both forms of the invention the roof elements are supported by the base structure for pivotal movement from an extended to a collapsed configuration.
In the Osterhoudt patent the ground engaging base structure comprises pivotally interconnected members 18 and 20 to which the several roof elements are pivotally attached.
Unlike the prior art structures, the novel shelter of the present invention does not embody any type of ground engaging base structure. Rather, in the super-structure of the present invention, the pivotally interconnected structural members which form the enclosure are adapted to pivot about points elevated substantially above ground and only the end portions of the vertically disposed structural members touch the ground. In this way, the structural members, as well as the various pivot pins about which the members pivot, are protected from damage caused by corrosion resulting from engagement with the ground.
Additionally, because of the absence of a ground engaging base, the shelter of the present invention is considerably lighter and easier to manipulate than the prior art shelters of conventional design. Further, by eliminating the necessity for a ground engaging base structure, the number of structural components necessary to form the shelter can be minimized thereby reducing the cost of manufacture of the device.
Still another improvement of the shelter of the present invention over those of the prior art resides in the fact that, due to the minimum number of structural members employed and the unique sizing of these members, the shelter can be collapsed into a highly compact configuration with the structural members nesting within one another in a most novel fashion.
A further factor which differentiates the apparatus of the present invention from the prior art structures of typical construction is that the vertical frame members of the structure of the present invention pass along side the horizontal frame members forming "cross" intersections. In the prior art structures, the vertical and horizontal intersecting frame members typically terminate at the horizontal frame members thus forming "T" intersections.
In sharp contradistinction, the leg portions of the vertical frame members of the present invention continue as one unbroken piece of material past the pivot points. This provides the unique cooperative interaction of the structural members of the invention not found in the prior art structures.
Other advantages of the shelter of the present invention will become apparent from the discussion which follows.